Apparatus for condensing steam



Nov. 25, 1930. D. K. DEAN 1,782,986

APPARATUS FOR CONDENSING STEAM Filed Sept. 19, 1928 A6 7'0 Al PUMPINVENTOR 0/0 6 Dad/2.

ATTORN EY Patented Nov. 25, 193i) UNITED STATES .PArsnr ,OF'FICE DION K.mum, on RAHWAY, NEW JERSEY, AssIeNon Tandems consona- 'IION, or newYORK, 1v. Y., A conronamro'n or NEW 0113 I APPARATUS FOR connnnsrne scumApplication fl1ed-September19,1928 Serial no. 808,988.

This invention relates to apparatus for effectin g a substantially equallongitudinal distribution of steam within the condenser casmg.

5 In a steam condenser, wherein the cooling medium makes a single passthrough the tubes from inlet to outlet, and the steam flows transverselyacross the tubes, the temperature of the tubes at the inlet is lowerthan at the outlet, for the reason that the coolin medium is heated bythe heat absorbed rom the steam, and the temperature increasesprogressively along the length of the tubes.

The steam at the warmer end of the condenser penetrates the tube bank toa greater depth than at the colder end, because at the warmer end thecondensing capacity is less. As a result of this condition, the steam atthe cooler end of the condenser does not reach and contact with thelowest tubes in the bank.

Also, the vapors leaving the warmer end contain a larger amount ofuncondensed steam thanat the cooler end and as the evacuatingapparatusis a limiting factor, the amount of air withdrawn from the condenser isnot at a maximum, although at the cooler end the air is efiicientlycooled. These conditions re sult in ineflieient operation of thecondenser.

Various schemes have been suggested for securing longitudinaldistribution of and stantially equal depth of penetration of the steamsuch as bafile plates at the steaminlet,v valves' at-the steam inlet andat the outlets, the use of an orifice plate in the branch of the,

36 air'lineattached to the compartment of the condenser in which thedepth of steam enetration is greater. All of these expe ients impose'anartificial resistance and somewhat reduce the advantage gained by bettersteam distribution.

proper steam distribution without imposing any n 'preeiablelartificialresistance. The invention contemplates the use of an air cool: er orauxiliary condenser in which the cooling capacity is adjusted to" therequirements of the various compartments of the main condenser; for examle, from that compartment in which the epth'of steam penetration isgreatest and from which steam laden air It is the object of thisinvention to secure will be drawn to the evacuatoi', .a connection ismade to a section of the air cooler having the greater cooling capacity.Y

The invention will be clearly understood by reference to the accomanying drawing forming a part of the speci cation, in which,

Fig. 1 is a view, in elevation and partly in section, of a-single passcondenser .and one form of auxiliary cooler, and

Fig. 2 is another form of auxiliary cooler arrangement with a singlepass condenser.

The condenser proper, shown in Fig. 1', consists of an outer shell 1rovided with a bundle or nest of water'tu es 2, supplied with coolingwater from the inlet 3 and discharging through the outlet 4.Substantially midway of the two ends of the condenser, there is apartition plate 5, substantially tight and serving also to support thetubes, which are of considerable length. The steam inlet" 6 is locatedso thatthe partition 5 will divide the flow of steam into two paths, onedirected into the compartment toward the water inlet 3 and the otherinto the compartment toward the outlet 4 By this arrangement there areestablished two condensing zones or sections and two paths for the flowof steam transverse to the flow of the cooling medium. When desirablethe condenser may be divided into more than two sectionsor zones and byproper means more than two paths for the flow of steam may beestablished.

In Fig. 1 there is shown an auxiliary condenser or air cooler 11,provided with a water or other cooling medium inlet 8 and outlet 9 andtubes 10 for the passage of the cooling medium through the cooler 11,from end to end inxone pass. A partition 12 is provided and so locatedas to provide a space to the right of saidpartition of greater area andvolume than thatto the left of said partition. The tubes 10 in the spaceor section to the right of the partition 12 have not only a greaterexposed surface but a longer path for water flow,and hence greatercondensing capacity, than do the tubes 10 in the space or section to theleft of said partition 12.

Without provision of any sort for longitudinal distribution of thesteam,in a single pass condenser of the type shown, in the comtures.

partment or zone to the left of the partition plate 5, nearest thecooler end of the condenser, the steam will be completely condensed inthe upper portion of the bundle of tubes and the lower tubes will dosubstantially no work. The tubes 2 in the section or zone to the rightof the partition 5, nearer the outlet, have become warm because of theabsorption of heat from the steam, and hence the depth of steampenetration is greater, covering substantially the lowermost tubes, andlikewise the condensing capacity is less. These conditions result ininefiiciency of operation. To remedy this defect and secure properlongitudinal distribution of thesteam, and substantially equal depth ofpenetration from end to end of the condenser (which may be determined bythe relative proportions of steam and air at the exits of the differentzones or compartments, the steam penetration being equal if theproportions of steam to air at the exits are substantially equal), theZone or section of the condenser to the right of partition 5 isconnected by the pipe 13 with the section of the cooler 7, having thegreater cooling capacity, to the right of its partition 12 and thesection of the condenser to the left of the partition 5, which iscooler, is connected by pipe 14 to the section of the cooler to the leftof its partition 12, which is of lesser cooling capacity.

As an example of the described control of the temperatures at the air.outlets of the compartments of the condenser, it may be assumed that thesteam which enters inlet 6 of the condenser contains about ten cubicfeet of air per minute measured at atmospheric pressure and at ordinarytempera- If the division of the steam into the two paths issubstantially equal between the two compartments, an equivalent of fivecubic feet of air per minute would be flowing through each compartmentand upon leaving the condenser at the two air outlets 13 and 14, wouldbe saturated with water vapor at the temperatures existing at theseexits and at the absolute pressure within the condenser. Assuming thisabsolute pressure to be two inches of mercury and that the air of thewarmer end of the condenser leaves the exit 13 at a temperature of 95degrees, the volume of the mixture of vapor and air at this end of thecondenser will be approximately 44.0 cubic feet per minute. At thecooler end of the condenser, assuming that the temperature of the vaporsat the exit is 90 degrees, the volume of the vapors at this end will beapproximately 260 cubic feet per minute,-

making a total volume of Vapors to be abstracted by the evacuatingapparatus (not shown but connected to the air outlet 15) from thecondenser of approximately 700 cubic feet per minute.

If, assmning the steam, air distribution, air quantity and vacuum, asset forth, the

temperature of vapors leaving the warmer end of the condenser is reducedto 92.5 degrees by passing through the air cooler section, the volume ofvapors abstracted and entering the evacuating apparatus from the warmerzone of the condenser, will be 320 cubic feet per minute instead of 440cubic feet per minute. This reduction in the quantity of vapor to beremoved from the warmer end will make it possible for the evacuatingapparatus to abstract a greater quantity of vapor from the colder endwith the result that the depth of steam penetration in the cooler endwill be greater than it would be had there been no reduction oftemperature at the warmer end due to the cooling effect of the aircooler in communication with this end of the condenser.

Substantially an ideal condition is obtained when the temperature of theair leaving the two compartments is substantially the same. Upon theassumptions made these temperatures would be approximately 92.5 degrees.

The total volume of vapors leaving the condenser as stated, at 92.5degrees, and two inches absolute pressure of mercury, would beapproximately 640 cubic feet per minute. As an evacuating apparatuscapable of operating under the original assumption will. have a capacityof 700 cubic feet per minute it will be capable of maintaining a highervacuum withinthe condenser because of a decrease in the quantity ofvapor which handled. This improvement in vacuum will also be enhanced byreason of the fact that the active steam is brought into contact withmore surface by reason of the greater depth of penetration at the coolerend of the condenser.

In Fig. 2 there is illustrated an alternative arrangement wherein twoair coolers or auxiliary condensers 7 and 7 are shown, each incommunication, through the respcctive connections 13 and 14", with thecompartments or zones of the condenser. Each of these coolers may be ofthe same size or the cooler 7 in communication with the warmer end ofthe condenser may be of larger cooling capacity. The coolers areprovided with water supply piping having the inlet 16 and outlet 17, thepath for the flow dividing; one branch 18 extending to the cooler 7" andthe other branch 19 extending to the cooler 7, each branch controlled bythe valves 20 and 21 respectively. By means of such arrangement thecooling surface may be adjusted, either manually or automatically bythermostatic control, to pass a larger amount of water through thecooler 7 b than through the other cooler and thus provide for greatercooling capacity in that cooler connected with the warmer end of thecondenser. Y

The specification illustrates and describes a single pass condenser towhich has been maaese applied the described cooling arrangement, but itis to be understood that the apparatus and method for cooling is equallyadaptable to a multi-pass condenser. The condenser and air cooler shownare each provided with two compartments. The air cooling arrangement isequally adapted to any number of condenser compartments or zones.

What I claim is:

1. In condensing apparatus comprising a main condenser having apluralityof compartments in each of which the condensing capacity isdifierent,the combination therewith of means for equalizing the depth ofsteam penetration in said condenser compartments comprising an auxiliarycondenser and air cooler provided with a plurality of cooling sections,each of such cooling sections having a different cooling capacity, meansfor connecting the cooling section having the greatest cooling capacitywith that condenser compartment in which the steam penetration isdeepest, means for connecting the cooling section having lesser coolingcapacity with a condenser compartment in which the steam penetration isnot so deep, and an evacuating apparatus connected to saidcooler. 2. Incombination witha condenser having tubes with unequal condensingcapacities in zones along their length, means for equalicing depth ofsteam penetration in such zones comprising a plurality of coolingmembers of difi'erent cooling capacities, that cooling member ofgreatest capacity being connected to that condenser zone in which thedepth of steam penetration is greatest, and a cooling member of lessercooling capacity being connected to a condenser zone in which the depthof steam penetration is not so great. 1

3. In combination with a condenser having two condensing compartments,evacuating apparatus for said condenser, an auxiliary condenser and aircooler located between the condenser and the evacuating apparatus, saidcooler being divided into two sections of different cooling capacities,means for connecting the cooler section of the greater capacity withthecondenser compartment the tubes of which are hotter, and meansforconnecting the cooler section of lesser capacity with the condensercompartmerit the tubes of which are cooler.

4. Apparatus of the, character described comprising a relatively largeshell having a vapor inlet, means for dividing said shell into aplurality of'vapor compartments, a relatively small shell, means fordividing said small shell into a. corresponding plurality ofcompartments, conduits connecting the compartments of said large shellindividually with the compartments of said small shell to form pairs ofconnected compartments,

means for passing cooling fluid through the compartments of said largeshell in series and through the compartments of said small shell inseries and in inverse order with respect to the respective compartmentsof said pairs, and means to withdraw fluid from the compartments of saidsmall shell.

5. Condensing apparatus comprising a main condensing member divided intoa plurality of relatively large compartments of 6. In combination with acondenser hav-' ing tubes with unequal condensing capacities in zonesalong their length, a plurality of cooling members for equalizing depthof steam penetration in said zones, said cooling members havingdifferent cooling capacities and being of smaller size than the zones ofthe condenser, a conduit connecting that cooling member of greatestcooling capacity with that condenser zone in which the depth of steampenetration is greatest, and a conduit connecting a cooling .member oflesser cooling capacity with a condenser zone in which the depth ofsteam penetration is not so great.

' DION K. DEAN.

